diff options
Diffstat (limited to 'drivers/media/v4l2-core/v4l2-i2c.c')
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-i2c.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/v4l2-i2c.c b/drivers/media/v4l2-core/v4l2-i2c.c new file mode 100644 index 000000000000..5bf99e7c0c09 --- /dev/null +++ b/drivers/media/v4l2-core/v4l2-i2c.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * v4l2-i2c - I2C helpers for Video4Linux2 + */ + +#include <linux/i2c.h> +#include <linux/module.h> +#include <media/v4l2-common.h> +#include <media/v4l2-device.h> + +void v4l2_i2c_subdev_unregister(struct v4l2_subdev *sd) +{ + struct i2c_client *client = v4l2_get_subdevdata(sd); + + /* + * We need to unregister the i2c client + * explicitly. We cannot rely on + * i2c_del_adapter to always unregister + * clients for us, since if the i2c bus is a + * platform bus, then it is never deleted. + * + * Device tree or ACPI based devices must not + * be unregistered as they have not been + * registered by us, and would not be + * re-created by just probing the V4L2 driver. + */ + if (client && !client->dev.of_node && !client->dev.fwnode) + i2c_unregister_device(client); +} + +void v4l2_i2c_subdev_set_name(struct v4l2_subdev *sd, + struct i2c_client *client, + const char *devname, const char *postfix) +{ + if (!devname) + devname = client->dev.driver->name; + if (!postfix) + postfix = ""; + + snprintf(sd->name, sizeof(sd->name), "%s%s %d-%04x", devname, postfix, + i2c_adapter_id(client->adapter), client->addr); +} +EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_set_name); + +void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client, + const struct v4l2_subdev_ops *ops) +{ + v4l2_subdev_init(sd, ops); + sd->flags |= V4L2_SUBDEV_FL_IS_I2C; + /* the owner is the same as the i2c_client's driver owner */ + sd->owner = client->dev.driver->owner; + sd->dev = &client->dev; + /* i2c_client and v4l2_subdev point to one another */ + v4l2_set_subdevdata(sd, client); + i2c_set_clientdata(client, sd); + v4l2_i2c_subdev_set_name(sd, client, NULL, NULL); +} +EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init); + +/* Load an i2c sub-device. */ +struct v4l2_subdev +*v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev, + struct i2c_adapter *adapter, + struct i2c_board_info *info, + const unsigned short *probe_addrs) +{ + struct v4l2_subdev *sd = NULL; + struct i2c_client *client; + + if (!v4l2_dev) + return NULL; + + request_module(I2C_MODULE_PREFIX "%s", info->type); + + /* Create the i2c client */ + if (info->addr == 0 && probe_addrs) + client = i2c_new_probed_device(adapter, info, probe_addrs, + NULL); + else + client = i2c_new_device(adapter, info); + + /* + * Note: by loading the module first we are certain that c->driver + * will be set if the driver was found. If the module was not loaded + * first, then the i2c core tries to delay-load the module for us, + * and then c->driver is still NULL until the module is finally + * loaded. This delay-load mechanism doesn't work if other drivers + * want to use the i2c device, so explicitly loading the module + * is the best alternative. + */ + if (!client || !client->dev.driver) + goto error; + + /* Lock the module so we can safely get the v4l2_subdev pointer */ + if (!try_module_get(client->dev.driver->owner)) + goto error; + sd = i2c_get_clientdata(client); + + /* + * Register with the v4l2_device which increases the module's + * use count as well. + */ + if (v4l2_device_register_subdev(v4l2_dev, sd)) + sd = NULL; + /* Decrease the module use count to match the first try_module_get. */ + module_put(client->dev.driver->owner); + +error: + /* + * If we have a client but no subdev, then something went wrong and + * we must unregister the client. + */ + if (client && !sd) + i2c_unregister_device(client); + return sd; +} +EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev_board); + +struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev, + struct i2c_adapter *adapter, + const char *client_type, + u8 addr, + const unsigned short *probe_addrs) +{ + struct i2c_board_info info; + + /* + * Setup the i2c board info with the device type and + * the device address. + */ + memset(&info, 0, sizeof(info)); + strscpy(info.type, client_type, sizeof(info.type)); + info.addr = addr; + + return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, &info, + probe_addrs); +} +EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev); + +/* Return i2c client address of v4l2_subdev. */ +unsigned short v4l2_i2c_subdev_addr(struct v4l2_subdev *sd) +{ + struct i2c_client *client = v4l2_get_subdevdata(sd); + + return client ? client->addr : I2C_CLIENT_END; +} +EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_addr); + +/* + * Return a list of I2C tuner addresses to probe. Use only if the tuner + * addresses are unknown. + */ +const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type) +{ + static const unsigned short radio_addrs[] = { +#if IS_ENABLED(CONFIG_MEDIA_TUNER_TEA5761) + 0x10, +#endif + 0x60, + I2C_CLIENT_END + }; + static const unsigned short demod_addrs[] = { + 0x42, 0x43, 0x4a, 0x4b, + I2C_CLIENT_END + }; + static const unsigned short tv_addrs[] = { + 0x42, 0x43, 0x4a, 0x4b, /* tda8290 */ + 0x60, 0x61, 0x62, 0x63, 0x64, + I2C_CLIENT_END + }; + + switch (type) { + case ADDRS_RADIO: + return radio_addrs; + case ADDRS_DEMOD: + return demod_addrs; + case ADDRS_TV: + return tv_addrs; + case ADDRS_TV_WITH_DEMOD: + return tv_addrs + 4; + } + return NULL; +} +EXPORT_SYMBOL_GPL(v4l2_i2c_tuner_addrs); |